Pathology
T he Facts
How safe is the pathology
testing process?
Australia’s pathology
laboratories process about 500
million pathology tests each
year. Here is a snapshot of
that process, including some
questions to consider.
Did you
know?
Pathologists
may
need
to
review up to 90 slides under a
microscope to diagnose one case
of cancer.
Does anyone regulate
the safety and
quality of pathology
laboratories?
A c c r e d i t a ti o n
is
p e r fo r m e d
against standards developed and
maintained by the National Pathology
Accreditation Advisory Council
(NPAAC), which is a ministeriallyappointed expert Council that
provides advice to the Australian
Government and State and Territory
Ministers on matters relating to
the accreditation of pathology
laboratories. NPAAC plays a key
role in ensuring the quality of
Australian pathology services. The
National Association of Testing
Authorities (NATA), which is an
independent assessing body, and
the Royal College of Pathologists of
Australasia (RCPA) jointly perform
an accreditation assessment of
pathology laboratories seeking
approval as an Approved Pathology
Laboratory.
This accreditation process is
compulsory for tests funded through
Medicare and ensures Medicare
benefits are only paid for pathology
services performed to a high
standard of accuracy. Potential risks
to patients are also addressed by
these standards.
How do I know if a
pathology laboratory
is accredited?
Look for the NATA/RCPA logos or
endorsement certificates that should
be clearly displayed in collection
centres or pathology laboratories, or
ask the pathology laboratory staff if
they have NATA/RCPA certification.
Patients can also refer to the NATA
website www.nata.com.au which
lists all Medical Testing laboratories
currently accredited in Australia.
How safe is pathology
testing? Are there
any risks?
The request-test-repor t cycle
represents the pathology testing
process and can be divided into three
main stages:
1.The pre-analytical stage covers all
aspects of the process before the
sample is tested
2.The analytical stage is the actual
testing of the sample
Did you
know?
Even though pathologists are
involved in the majority of medical
episodes, there are very few
reported cases of negligence
involving pathologists.
3.The post-analytical stage covers
the steps after the sample is
analysed.
Other important but
rare risks include:
•
Are there any risks?
The highest risk in the pathology
process is when a person presents
to have their sample collected. If the
person is not identified correctly,
or the pathology sample and/or
request form do not have the correct
information about the correct person,
the results may be attributed to
another person or treatment may
be delayed or missed. For example,
a person can be transfused with
the wrong blood type if they are not
correctly identified.
More than 97% of all pathology
specimens are analysed without
incident. About 2% of pathology
specimens have a minor issue that
may require clarification and delay
the result. Less than 1% of pathology
specimens have a problem that
prevents the result being issued
safely, or requires collecting another
sample.
the sample may be degraded by
being transported incorrectly. The
risk to a person is usually minimal
and might involve collecting
another sample
•
the actual testing of the sample
may not be performed accurately
in the analytical stage. This risk
is monitored and controlled by
quality assurance processes
required by all accredited
pathology laboratories
•
r eports issued in the postanalytical stage may contain
incorrect results that need to
be withdrawn and the report reissued.
Are all pathology
specimens analysed
by machines?
Some areas of pathology are highly
automated and involve placing
multiple specimens, such as tubes
of blood, into sophisticated machines
called analysers. These highly
automated instruments can analyse
the specimens quickly with minimal
human assistance, although highly
skilled staff are still required to ensure
the equipment is operating effectively
and producing the correct results.
Other areas of pathology are very
labour intensive and cannot be
automated. For example, tissue
samples or slides viewed under
a microscope must be manually
prepared and individually assessed
by pathology staff.
What are reference
intervals?
Reference intervals (or “ranges”),
provided by the pathology laboratory
in their report, are required to guide
treating practitioners when they
interpret a pathology test result. They
may be specified by age and gender,
and may take other characteristics
into account such as a pre-existing
medical condition. The most widely
used reference intervals reflect
the values of 95% of a ‘healthy’
population.
Did you
know?
Pathology
laboratories
are
leaders in the medical profession
in monitoring and reducing rates
of errors and adverse incidents.
All
pathology
must
par ticipate
laboratories
in
quality
assurance programs that test
their performance as part of their
accreditation requirements. They
must also actively investigate
any actual or potential errors and
demonstrate corrective actions
in their procedures to prevent
similar errors from occurring
again.
What are false
positive and false
negative results?
False positive results occur when a
person tests positive for a disease
or condition they don’t have. False
negative results occur when a
person tests negative for a disease or
condition they do have. These occur
because reference intervals are only
a guide which means some healthy
people will have results outside of
this range, and some people will have
results within this range, even when
they are ill.
Are all pathology
laboratories the
same?
Did you
know?
While all accredited pathology
laboratories are required to meet
the same quality standards, not
every pathology laboratory is the
same. Some have particular areas
of expertise while others are located
in particular locations, such as near
a hospital or in a rural area, and
their services reflect their patients’
needs. Patients, and their treating
practitioners, should be comfortable
with the capabilities, location,
services offered and fees charged by
their chosen pathology laboratory.
Patients can help pathology
la bor ator y
staf f
minimis e
the possibility of an error by
checking self-collected samples
are labelled with the correct
information.
95%
(950 people)
2.5%
(25 people)
‘abnormally’ low values
2.5%
(25 people)
Reference interval
‘abnormally’ high values
Possible outcomes of any pathology test
Likelihood of having a disease
‘Normal’ level for
a healthy person
Healthy people
People with disease
True
negatives
False negatives
True
positives
Did you
know?
False positives
There are some healthy people who
Since 95% of healthy people fall
test positive for a disease (false
inside the set reference interval,
positive) and some people with a
the other 5% of healthy people will
disease who test negative (false
have a result outside of this range
negative)
and have a pathology test result
that is apparently ‘abnormal’. This
means that even perfectly healthy
people can have a result outside
of the reference interval which
highlights the importance of
interpreting pathology test results
against other factors such as
age, symptoms and past medical
history.
Reliable information on pathology can be found at:
The Royal College of Pathologists of Australasia (RCPA) - www.rcpa.edu.au
ePathWay (the RCPA’s online magazine for consumers) - http://epathway.rcpa.edu.au
The RCPA Manual - http://rcpamanual.edu.au
The Pathology Associations Council (PAC) - www.pathology.med.pro
Lab Tests Online - www.labtestsonline.org.au
The RCPA wishes to acknowledge the Australian Government Department of Health and Ageing
for funding the production of Benefits and Risks for Consumers of Pathology Testing